This project is to characterize a recently described caprine disease, arthritis-leukoencephalitis of goats (ALG). The causative virus will be isolated by co-cultivation of a number of cell strains from the brain and the joints of affected goats with an established cell line. The virus will be characterized according to its biochemical properties, and classified if possible. The nature of virus-cell interaction extant in the latent infection of brain cells will be explained. Whether the infection is latent, or a steady state relationship exists will be determined. Antisera will be raised against the virus, and used to develop a fluorescent antibody system for detection of viral antigens in vivo and in vitro. The distribution of virus during acute and chronic disease and the sites of persistence will be determined with the FA system. Where necessary, this data will be supplemented by neonatal goat inoculation of tissue to test for virus. Various immunologic procedures will be used to define the humoral and cellular immune response to the virus. Samples from a herd naturally infected with the virus, collected over a period of two years, will be titrated for antibody, and a search conducted for correlations between antibody titers in the dam or kid and susceptibility or resistance to disease. The prevalence of antibody to this virus in the goat population will be determind by bleeding farm flocks. The influence of age on susceptibility to the two syndromes, CNS and connective tissue, will be determined by injecting goats at various ages with defined virus inocula. A herd of goats with chronic disease of joints and brain will be assembled and maintained for purposes of further studies on pathogenesis, virology and immunology of ALG.